Writing a bass line for a given soprano

1. Determine cadences. 2. Determine if a predominant is involved with the cadence. 3. Plot unequivocal tonic function throughout the phrase. 4. Devise ways to prolong tonic function throughout the phrase.

a. Prolonging, rather than sitting on, the tonic chord provides tension and release, which helps to create a flow within the phrase.

5. Prolong predominant and dominant, if necessary.

Voice leading for the bass line

1. Make the bass line as melodic as possible. 2. The bass line may have more leaps than a typical soprano line, while maintaining an interesting

contour. 3. Inversions:

a. Root position chords provide stability to the sound. b. First inversion chords allow the bass line to be more melodic. c. Second inversion chords should be one of:

i. Passing six-four ii. Auxiliary (neighbor/pedal) six-four

iii. Cadential six-four d. Third inversion seventh chords contribute to the melodic nature of the bass line and

provide tension that is released in the following first-inversion chord (e.g., V42 – I6 ).

4. Rhythmically and melodically, the bass line should be both independent and interesting. a. Use a variety of motion between soprano and bass

i. Static (repeated notes; use sparingly) ii. Parallel motion (no more than four consecutive; provides unity, not

independence, between the lines) iii. Similar motion (provides moderate independence) iv. Contrasting (provides the greatest independence between the lines) v. Oblique (more independence than parallel/similar motion but less than

contrasting)

Writing in three parts

1. The horizontal voice leading is the most important consideration. 2. Use complete triads whenever possible.

a. If a complete triad is not possible, try to use two roots and a third. 3. Seventh chords

a. Three different pitches should be used. b. The root should be present.

4. All three voices should be as independent as possible. a. Avoid too many consecutive thirds between the soprano and alto.

Writing in four parts

1. The horizontal voice leading is the most important consideration. 2. Root position triads

a. Use two roots, a third, and a fifth, unless the horizontal voice leading requires a different voicing.

i. In the progression from V-vi, it is possible for the vi chord to have a doubled third, due to the resolution of the leading tone.

ii. In a minor key the doubled third is required to avoid an augmented second. b. When root position chords a second apart appear in succession, the three upper voices

must move contrary to the bass in order to avoid parallel fifths and/or octaves. i. An exception to this is the V-vi progression mentioned above.

c. The seventh of a non-dominant seventh chord should be approached by common tone. 3. First inversion triads

a. If the triad is diminished, double the third (bass), else, If the note in the bass is a primary scale degree (1, 4, 5), double the third (bass), else, Double a note other than the third (bass).

4. Second inversion triads a. When voicing a triad in second inversion, always double the fifth (bass).

5. Seventh chords. a. The best voicing includes all four pitches. b. The fifth may be omitted to avoid a voice leading error. In this situation, double the

root. c. Seventh chords of any type may appear in any inversion.

6. The four voices should be as independent as possible. 7. Spacing between adjacent upper voices (soprano/alto; alto/tenor) must not be more than an

octave. a. It is possible to have more than an octave between tenor and bass; normally, we do not

exceed a twelfth.